1. Field of the Invention
The invention relates to a clamping device for a mold unit, more particularly to a clamping device that can quickly clamp a mold unit against a mold holder.
2. Description of the Related Art
Referring to FIG. 1, a conventional injection-molding machine 10 is shown to include an injection unit 12 mounted on one side of a platform 11 of the machine 10, and a mold support 13 mounted on the other side of the platform 11. The mold support 13 includes a stationary mold holder 131, a fixed seat 132 mounted opposite to the stationary mold holder 131, a plurality of parallel guide rods 133 disposed between the stationary mold holder 131 and the fixed seat 132, a movable mold holder 134 mounted slidably on the guide rods 133, and a hydraulic cylinder 16 connected to the fixed seat 132 and the movable mold holder 134. The stationary and movable mold holders 131, 134 have confronting surfaces connected respectively to first and second mold units 151, 152 using a plurality of bolts 14. The first and second mold units 151, 152 cooperate to form a mold set 15 so as to proceed with an injection molding operation.
Although the aforementioned mold support 13 can achieve its intended purpose, in actual use, since the mold units 151, 152 are fixed to the mold holders 131, 134 through the bolts 14, the following disadvantages are encountered:
1. The operation for tightening the bolts 14 is time-consuming.
2. An operator has to exert a relatively large force to tighten the bolts 14.
Another conventional device (not shown) for mounting the mold units 151, 152 on the mold holders 131, 134 includes a plurality of hydraulic die clamps (not shown) provided on each of the stationary and movable mold holders 131, 134. Each of the hydraulic die clamps includes a hydraulic cylinder, a pivot seat, and a lever-type clamp piece connected pivotally to the pivot seat. Through the action of the hydraulic cylinder on the clamp piece, the first and second molding units 151, 152 are clamped, respectively. However, because this kind of conventional clamping device uses the hydraulic cylinder, the following disadvantages are encountered:
1. Increase in auxiliary parts, such as a pump, a control unit, a pressure sensor, a hydraulic pipeline, connectors, etc.
2. Price is expensive.